Chromium plated abticle and method



Patented July 16, 1935 UNITED STATES PATENT. OFFICE CHROMIUM PLATED ARTICLE AND METHOD I OF MAKING THE SAME William H. Keen, Albany, NQY.

SCIaims.

The present invention relates to chromium plated articles and has as an object to provide a corrosion resisting product of good quality,

whlchwill he commercially satisfactory and possible of manufacture at low cost,

The invention has been evolved in connection with the development of cutlery and such an aweent will he more particularly described forthe purposes of disclosure of the principles of the invention, but it will be understood that the description is illustrative merely and not intended as de A: the limited the invention.

ti'utlery made oi the best quality of corrosion resisting high chromium steel has become extremely popular dg the last several years, but the cost of the steel limits its use to a field in which the requirement of quality is primary. in order to meet the demand for low price cutlery, attempts have been made to provide a less expensive article by chromium plating other steels, such as carbon steel. Knives of this manufacture, however, have been unsatisfactory in use for the reason that when the chromium plate is odes. The result has been that the ui'eoture of knives of this type has been abandoned as not producing a commercially satisfactory article, The present invention provides an improved I m ole which is no of a corrosion resisting steel chromi pluted. The steel offers suficient reslstetnce to corrosion so that when exposed lay the removal of the chroum plate, it will still present a satisfactory appece. The uality of the steel, furthermore, is such that a satisfactory sharp edge can he maintained on wives.

@utlery produced in accordance with the present invention has the ier advantage that the chroini plate is hard and resistant to scratches. In fact, in this particular regard it is superior to coercial stainless deal cutlery. It s e which is noticeably superior in oponce to the ordinury glaze and nly equal to the popular "or The composition of the steel alloy should he so selected as to provide a reasonable resistance to corrosion under the conditions of use when hy the partial removal of the chromi piele end it should he of a quality to maintain a satisfactory edge, in the case of knives, in order to meet c'oercial resents. At the same e the composition should he one which can be utectured at a relatively low cost. A steel either by the wear due to use or by of the knife, the exposed cteelmeeting these requirements may contain, for example, approximately.

Per cent Carbon 0.05m 1.20 Chro m 5.00tol2.00 5 Silicon 000th 0.50 Manganese 0.20to 0.80

with the reminder principally iron. There are certain advantages in adding a small griount of magnesium, as, for example, 0.10 to 0%. I it will he understood that other elements such as are ordinarily found in steel either as impurities or as desirable components may he present in this steel, in the event that corresponding properties are desired or a less expensive product is preferred. Such steels may contain, for example, nickel, vanadium, molybdenum, tungsten or other elements required to produce character- 20 istic properties that may he desired.

A preferred steel providing knives of good quality may contain approximatelytoll "Ear

vStcelsoi the compositions n- I t: be forged or rolled and can he nruoed at shout ve- 2 the cost of steels M35410, wing t t y accepted a for good qualit? 00 is. v: we

ves are preferably e and tetnpe 35' rolled seal and t5 avoid the rdening and tempo operation,

may he done although somewhat at the er:- of corrosion resistance. For such wou d a lower cerhon content as from 0.05 to ll.25% is preferable thus providing a still low expensive product and one which will still have commercially acceptable corrosion its. 2

Alugh the lore tdescrintion relates to chromium plated cutlery, it I l b m that other plating terial such as silver, cadmium, tin or nickel can be substituted and the broader features of the invention can be applied to other articles such as automobile parts including bumpers, fenders and the like and even to roofing without exceeding the scope of the invention as defined in the appended claims.

I claim- 1. A corrosion resisting article fabricated from a steel'containing approximately 0.30 to 0.i0% carbon, 5 to 9% chromium and 0.20 to 0.40% magnesium with the remainder principally iron, said article being plated with a. metal oi the group consisting of chromium, silver, cadmium, tin and nickel, said platingbeing molecularly in the same condition as when first applied.

2. A corrosion resisting knife fabricated from.

steel containing approximately 0.05 to 0.40% carbon, 5 to 9% chromiumand 0.2 to 2% magnesium with the remainder principally iron, said knife being in hardened condition as the result 0! heating and quenching and having a chromium plate surface which plate is molecularly in the same condition as when first applied.

3. The method of producing a knife which comprises fabricating the knife of a corrosion resisting steel containing approximately 0.05 to 0.4% carbon, 7 to 9% chromium, 0.2 to 0.4% magnesium with the remainder principally iron, hardening the same and thereafter plating it with chromium.

WILLIAMH. KEEN. 15 

